Epidemiology of rabies virus variants. Differentiation using monoclonal antibodies and discriminant analysis

Rabies virus was isolated by cell culture from the brains of 104 confirmed rabies cases diagnosed by the fluorescent-antibody staining technique in the United States during 1974-1984. Eighty-seven isolates were obtained from wild-life species, 10 from humans, and seven from domestic animals. These isolates were tested in virus neutralization and immunofluorescence assays using a panel of 34 monoclonal antibodies specific for rabies virus nucleocapsid protein, 44 monoclonal antibodies specific for rabies virus glycoprotein, and two monoclonal antibodies specific for rabies virus nucleocapsid-associated phosphoprotein. Using discriminant analysis, a distinctly different reactivity pattern was revealed between virus isolates from terrestrial (raccoon, skunk) and nonterrestrial (bat) reservoir hosts. The usefulness of this approach for studying the epidemiology of rabies and for predicting the source of infection when this information is unknown is discussed.     

Ullrich-Turner syndrome with a small ring X chromosome and presence of mental retardation

Since some patients with Ullrich-Turner syndrome (UTS) have mental retardation, we reviewed our experience to look for a high-risk subgroup. Among 190 UTS and gonadal dysgenesis patients with X chromosome abnormalities, 12 had mental retardation. All of the six (100%) with a small ring X were educable (EMI) or trainable mentally impaired (TMI) with more severe delay than expected in UTS. Among the 184 with other X abnormalities, only 6 had similar delays (2 from postnatal catastrophes), for a frequency of 3.3% mental retardation among those without a small ring X; only 2.2% of these had unexplained mental retardation. Polymerase chain reaction studies showed no Y-derived material in the 2 patients who were evaluated, and in situ hybridization confirmed X origin of the ring in the 6 subjects who were evaluated. We describe the phenotype of the 6 individuals with a small ring X, and an additional 2 patients with a small ring X who were identified outside the survey. The subjects with a small ring X comprised a clinically distinct subgroup which had EMI/TMI and shorter stature than expected in UTS. Seizures and a head circumference <10th centile were observed in half of the patients with a small ring X, and strabismus, epicanthus, and single palmar creases were present in more than half. A “triangular” face in childhood, pigmentary dysplasia, sacral dimple, and heart defects were also common. Neck webbing appeared to be less frequent than in 45, X. We hypothesize that the high risk of mental retardation in this form of the UTS results from lack of lyonization of the ring X due to loss of the X inactivation center. Excluding those with a small ring X, mental retardation is not significantly increased in patients with UTS. © 1992 Wiley-Liss, Inc.     

Void-Induced Ductile Fracture of Metals: Experimental Observations

The paper presents a literature review on the development of microvoids in metals, leading to ductile fracture associated with plastic deformation, without taking into account the cleavage mechanism. Particular emphasis was placed on the results of observations and experimental studies of the characteristics of the phenomenon itself, without in-depth analysis in the field of widely used FEM modelling. The mechanism of void development as a fracture mechanism is presented. Observations of the nucleation of voids in metals from the turn of the 1950s and 1960s to the present day were described. The nucleation mechanisms related to the defects of the crystal lattice as well as those resulting from the presence of second-phase particles were characterised. Observations of the growth and coalescence of voids were presented, along with the basic models of both phenomena. The modern research methods used to analyse changes in the microstructure of the material during plastic deformation are discussed. In summary, it was indicated that understanding the microstructural phenomena occurring in deformed material enables the engineering of the modelling of plastic fracture in metals.     

Multicomponent Low Initial Molar Ratio of SiO2/Al2O3 Geopolymer Mortars: Pilot Research

Alkali-activated binders have the potential to consume various types of waste materials. Low initial molar ratios of SiO₂/Al₂O₃ geopolymer mortars were considered in this article. Here we studied alkali-activated binders produced with photovoltaic glass powder in 5%; kaolin clay in 15%; ground granulated blast furnace slag in 30%; alumina-lime cement in 30%; and, interchangeably, fly ash from coal combustion in 5%, fly ash from biomass combustion in 5%, or granulated autoclaved cellular concrete in 5%. The influence of clay dehydroxylation, curing conditions, glass presence, and a kind of waste material was investigated. According to the experimental results, strength (compressive and tensile) gradually increased with increasing time and with the use of calcined clay. Significant improvement in compressive strength was seen with the additional 3 days curing time in 105 °C when non-sintered clay was used. The presence of photovoltaic glass in alkali-activated mortars immobilised mercury and arsenic but released zinc, chromium, and sulphates. The microscopic observations confirmed the greater densification of the microstructure of the binder made of calcined clay due to its greater surface development and dehydroxylation. The binder of non-calcined clay was granular, and the interfacial transitional zone was more porous. The C–A–S–H gel seemed to be the main phase. XRD examination confirmed the presence of C–A–S–H, C–S–H, zeolites, and many other phases in minor amount. The presented research was a pilot study, and its main goal was to develop it further.     

Applicability Assessment of Different Materials for Standards Ensuring Comparability of Optical and Tactile Coordinate Measurements

Multisensor CMMs are systems with an established position on the market, but their popularity still grows, as they provide access to the advantages offered by tactile and contactless measurement methods. Yet there are still questions of the comparability of results obtained using the optical and tactile operation modes of multisensor system. This phenomenon can be assessed by measuring appropriate gauges, most often reference rings or spheres. Due to the completely different nature of probing processes for tactile and contactless measurements, the material from which reference object is made may significantly affect measurement results. In order to assess the influence of this factor on measurement accuracy, three reference spheres made from different materials were measured on optical multisensor CMMs. Measurements involved tactile measurements as well as optical measurements made using different probing systems: a video probe and white light sensor. Results obtained from performed experiments show large differences depending on the material used for spherical standard production. On the basis of obtained results, it can be stated that the best material for a reference object that can be used for comparability tests of tactile and optical measurements is a composite of alumina with at least one oxidic additive.     

Extraction of Alkalis from Silicate Materials Part 1—Amorphous Silicate Materials

The main building materials widely used worldwide are those based on cement, glass, and ceramics. Taking into account the fact that the raw material base for the production of these materials is narrowing, and the quality of raw materials is declining, methods are being used to modify the structure of silicate materials in order to improve their properties when using cheaper raw materials and industrial waste, which should help reduce the energy intensity of their production. One of the ways to reduce energy consumption is the use of alkaline components in the chemical composition of silicate materials, which makes it possible to reduce the temperature of their synthesis. However, the presence of alkalis in the material at the stage of the operation is undesirable since it contributes, for example, to a decrease in the chemical resistance of silicate glasses or leads to the phenomenon of alkaline corrosion in cement products. In this regard, in order to reduce the negative impact of alkalis, it is necessary to extract them from the surface layers of the silicate material. There are various methods for extracting alkalis from silicate materials, some of which are presented in this article.     

Alkaline Activity of Portland Cement with Additives of Waste Glass

The concept of the alkaline activity of powdered materials introduced into cement compositions has been proposed, along with methods for its determination. The possibility of using waste glass as an active additive to Portland cement was evaluated from the standpoint of alkaline activity. Replacing the Portland cement component with glass waste in the form of glass powder at amounts from 1 to 35% made it possible to maintain the cement composition’s alkaline activity at a level that met the standard requirements. The previously unknown effects of mixed alkali in Portland cement in the presence of glass waste are described. Portland cement has a high potassium alkaline activity; however, container glass has a high sodium alkaline activity and a fairly low potassium alkaline activity. When glass waste is introduced into the structure of cement compositions, potassium alkaline activity is reduced.     

Dynamic structure of lipid-bound synaptobrevin suggests a nucleation-propagation mechanism for trans-SNARE complex formation

The synaptic vesicle protein synaptobrevin engages with syntaxin and SNAP-25 to form the SNARE complex, which drives membrane fusion in neuronal exocytosis. In the SNARE complex, the SNARE motif of synaptobrevin forms a 55-residue helix, but it has been assumed to be mostly unstructured in its prefusion form. NMR data for full-length synaptobrevin in dodecylphosphocholine micelles reveals two transient helical segments flanked by natively disordered regions and a third more stable helix. Transient helix I comprises the most N-terminal part of the SNARE motif, transient helix II extends the SNARE motif into the juxtamembrane region, and the more stable helix III is the transmembrane domain. These helices may have important consequences for SNARE complex folding and fusion: helix I likely forms a nucleation site, the C-terminal disordered SNARE motif may act as a folding arrest signal, and helix II likely couples SNARE complex folding and fusion.     

Serum level of beta-chemokine RANTES in patients with coronary artery disease

Chronic inflammatory process plays an important, as still not clear, role in pathophysiology of coronary artery disease (CAD), especially in acute coronary syndromes. Chemokines are present in atherosclerotic plaques and are essential factors in the recruitment of leukocytes and stabilization of atherosclerotic lesions. The aim of the study was the evaluation of RANTES serum level in patients with stabile CAD and seeking for correlations between RANTES serum level and progression of atherosclerotic lesions. The study included 83 patients from 22 to 87 years old, 41 women (mean age 61,2 +/- 12,5) and 42 men (mean age 58,8 +/- 15,4), who were admitted to the Cardiology Department for coronarography. After coronarography the patients were separated in 4 groups according to the presence of atherosclerotic lesions. Patients with atherosclerotic lesions were also divided depending on the severity of anginal pains to CCS II or CCS III classes. Blood samples for the measurement of RANTES serum level were taken at baseline conditions on the day after the admittance to the hospital. RANTES serum level was measured by enzyme-linked immunoabsorbent assay (ELISA) kit system (Endogen, MA, USA). There was not statistically significant differance in RANTES serum level between patients with CAD and subjects without atherosclerotic lesions in coronary arteries with or without arterial hypertension. Significantly higher levels of RANTES were observed in patients with atherosclerotic lesions in coronary arteries and anginal pains in CCS II class, than in patients with atherosclerotic lesions in coronary arteries and anginal pains in CCS II class, as well as in subjects without atherosclerotic lesions (respectively 58.5 vs 42.1 pg/ml and 54.5 vs 41.9 pg/ml, p<0.01). Significant positive corellations were found in patients with CAD between RANTES serum level and systolic blood pressure (r Pearson 0,291, p<0.05), and cholesterol (R Spearman 0.289, p<0.05). In all patients analysis of regression found significant correlation between RANTES serum level and systolic blood pressure (p 0.296, B 0.391, p<0.007). These results may indicate the active implication of chemokines in the pathophysiology of atherosclerotic lesions.     

„Der epidurale Blood Patch: ein Auftrag für den versierten Anästhesisten?“

Die Anaesthesiologie -